<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>

</head>
<style>
   *{
        margin: 0px;
        padding: 0px;
        list-style: none;
    }
    ul{
        width:800px;
        height: 800px;
        border: 1px solid red;
        /*将ul设置为弹性元素*/
        display: flex;
        justify-content: space-around;
          
    }

    li{
        width: 100px;
     
        font-size: 50px;
        text-align: center;
        line-height: 100px;
    align-items: flex-start;

    /*元素的空白分布
       center
       space-between
       ....
    */
    /* align-content: center; */
        
    }
    li:nth-child(1){
        background-color: royalblue;
    /* align-self: ; 单独设置元素的1方式，覆盖前面的align-items */
       
    }
    li:nth-child(2){
        background-color:red;
    
    }
    li:nth-child(3){
        background-color: blueviolet;
      
    }

</style>
<body>

      <ul>
          <li>
              1
<div>111</div>

          </li>
          <li>2
              <div>222</div>
              <div>222</div>
          </li>
          <li>3
              <div>333</div>
              <div>333</div>
          </li>
        
      </ul>
</body>
</html>
</html>